The present invention relates to electrical adapters and mounting apparatus. More particularly, the present invention pertains to adapters for packaged integrated circuit devices, e.g., ball grid array packages, flip chip packages, land grid array packages, etc., and mounting apparatus that may be used therewith.
Certain types of integrated circuit packages are becoming increasingly popular due to their occupancy area efficiency. In other words, they occupy less area on a target board on which they are mounted while providing a high density of contact terminals. For example, one such high density package type is a ball grid array package. Generally, ball grid array packages contain an integrated circuit having its die bond pads electrically connected to respective conductive solder spheres that are distributed on the bottom surface of the package in an array. A target printed circuit board typically has formed on its surface a corresponding array of conductive pads which are aligned with the array of solder spheres for electrically mounting the ball grid array package on the target board. The target board typically includes other conductive traces and elements which lead from the array of conductive pads used for mounting the ball grid array package to other circuitry on the board for connecting various components mounted thereon. Typically, to mount such a ball grid array package to a target board, the package is positioned with the array of solder spheres corresponding to the array of conductive pads on the target board. The resulting structure is then heated until the solder spheres are melted and fused to the conductive pads of the target board.
Such area efficient packaging, e.g., ball grid array packages or land grid array packages, provide a high density of terminals at a very low cost. Also, this packaging provides for limited lead lengths. The limited lead lengths may reduce the risk of damage to such leads of the package, may provide for higher speed product, etc.
Generally, circuit boards and/or components mounted thereon are tested by designers as the circuit boards are being developed. For example, for a designer to test a circuit board and/or a ball grid array package mounted thereon, the designer must first electrically connect the solder balls on the ball grid array package to the target circuit board. As described above, this generally includes mounting the ball grid array package on the target board and heating the solder spheres to fuse the solder spheres to the conductive pads of the target board. Therefore, the package may be prevented from being used again. It is desirable for various reasons to use package adapters for mounting the packages and reuse ball grid array packages after testing. For example, such ball grid array packages may be relatively expensive. Further, for example, once attached, the solder spheres are not accessible for testing. In addition, it is often difficult to rework the circuit board with the packages soldered thereon.
Various adapters for ball grid array packages which electrically connect a ball grid array package to a target printed circuit board without requiring that the solder balls on the ball grid array package be fused to the target board are known. For example, one such adapter is shown in U.S. Pat. No. 5,892,245 to Hilton, issued Apr. 6, 1999 and entitled, xe2x80x9cBall Grid Array Package Emulator.xe2x80x9d However, the high density of terminals for certain packages, e.g., ball grid array packages, lead to various interconnect problems for adapters being used with such packages. For example, such a high density of terminals, e.g., solder spheres, of such packaged devices may lead to isolation problems between conductive elements of conventional adapters used for connecting the packages to the target board. Further, many adapters require the provision of structure on the target board for mechanically fastening an adapter thereto. For example, in many cases the target board is required to have holes defined therein for receiving fastening devices to mechanically mount the electrical adapter to the target board. Yet further, alignment of the contact terminals of the packaged device, e.g., solder spheres, to the contact pads of the target board may be problematic when an electrical adapter is used. Still further, space limitations may prevent use of certain types of adaptors directly on a target board such as those including test probes.
The present invention provides packaged device adapter assemblies preferably useable for high density integrated circuit packages, e.g., ball grid array packages, flip-chip packages, chip scale packages, land grid array packages, etc., and also pluggable mounting apparatus, e.g., zero insertion force pluggable assemblies, such as may be used with such adapter assemblies.
A pluggable mounting apparatus according to the present invention provides for mounting a mountable structure having a plurality of contact elements on a surface thereof to a target having a plurality of contact elements on a surface thereof. The pluggable mounting apparatus includes a pin array portion comprising a body member extending along a mounting axis between a first end and a second end. The pin array portion includes a plurality of pin contact elements for electrical connection with the plurality of contact elements of the surface of the mountable structure. Further, at least portions of the plurality of pin contact elements extend from the second end of the body member.
The mounting apparatus further includes a mounting base including a base member and a wall member extending therefrom defining a cavity along the mounting axis sized to receive at least a portion of the body member of the pin array portion. The base member is positioned orthogonal to the mounting axis and includes a first set of contact elements and a second set of contact elements. The first and second sets of contact elements are electrically connected and disposed on opposing sides of the base member. The first set of contact elements is located within the cavity and the second set of contact elements is for electrical connection with the plurality of contact elements on the surface of the target.
Yet further, the mounting apparatus includes a conductive element layer that includes a plurality of arranged conductive elements. The conductive element layer is positioned in the cavity for electrical contact between the plurality of arranged conductive elements and the first set of contact elements and also for electrical contact between the plurality of arranged conductive elements and the portions of the plurality of pin contact elements extending from the second end of the body member of the pin array portion when the portion of the body member of the pin array portion is received in the cavity.
In one embodiment of the apparatus, the mounting apparatus further comprises an alignment structure positionable in the cavity adjacent the base member. The alignment structure includes an opening to receive and align the conductive element layer within the cavity. In another embodiment, the alignment structure includes one or more openings configured as a function of the portions of the plurality of pin contact elements extending from the second end of the body member. The one or more openings guide the portions of the plurality of pin contact elements for contact with the conductive element layer within the cavity. In yet another embodiment, the alignment structure includes an opening sized such that the alignment structure makes contact with the second end of the body member of the pin array portion when the at least a portion of the body member of the pin array portion is received in the cavity.
In other embodiments of the apparatus, the conductive element layer may be a conductive elastomer layer, the plurality of pin contact elements (e.g., flat head dual barb pins) extending from the second end of the body member may terminate in a flat end lying orthogonal to the mounting axis for contact with the conductive element layer, and/or the plurality of pin contact elements may include a contact pin element extending through the body member from the first end to the second end and terminating beyond the second end at a pin contact end for contact with the conductive element layer.
In yet another embodiment, the mountable structure includes a test probe adaptor structure having a plurality of contact elements on a surface thereof. The plurality of pin contact elements include a plurality of contact regions for electrical contact with the plurality of contact elements on the surface of the test probe adaptor structure.
A pluggable apparatus according to the present invention includes a body member extending along an axis thereof between a first end and a second end and a plurality of pin contact elements. Each pin contact element extends through the body member from the first end to the second end terminating beyond the second end at a pin contact end. At least one pin contact end is a flat end lying orthogonal to the axis.
In other embodiments of the pluggable apparatus, one or more of the plurality of pin contact elements may include a barb portion at the first end of the body member, one or more of the plurality of pin contact elements may include a barb portion between the first end and second end of the body member, and/or one or more of the plurality of pin contact elements are pins having a flat end and dual barb portions.
A mounting apparatus according to the present invention is also described. The mounting apparatus includes a mounting base including a base member and a wall member extending therefrom. The base member and wall member define a cavity along a mounting axis sized to receive a structure having a plurality of pins extending therefrom. The base member is positioned orthogonal to the mounting axis and comprises a first set of contact elements within the cavity electrically connected to a second set of contact elements. The first and second sets of contact elements are disposed on opposing sides of the base member. The mounting apparatus also includes a conductive element layer including a plurality of arranged conductive elements. The conductive element layer is positioned in the cavity such that the plurality of arranged conductive elements are in electrical contact with the first set of contact elements of the base member and also in electrical contact with the plurality of pins of the structure when received in the cavity.
In various embodiments of the apparatus, the mounting apparatus may include alignment structure such as described above, the conductive element layer may be a conductive elastomer layer, and the second set of contact elements of the base member may include solder spheres.
An adapter apparatus according to the present invention for receiving a packaged device, e.g., a land grid array, having a plurality of contact pads disposed on a surface thereof is also described. The adapter apparatus includes a base member including a first side and an opposing second side. The base member includes a plurality of solder spheres on the first side thereof electrically connected to a plurality of contact elements on the second side. The apparatus further includes a perimeter wall member having a length along an adapter axis between a first end of the wall member and a second end of the wall member. The first end of wall member is positioned adjacent the base member. A conductive element layer including a plurality of arranged conductive elements is positioned at the first end of the perimeter wall member orthogonal to the adapter axis. The perimeter wall member and the base member define a socket cavity to receive the packaged device with the plurality of contact pads thereof adjacent the conductive element layer. A cover member is positioned at the second end of the perimeter wall member to close the socket cavity. The cover member is movable to allow the packaged device to be removed from the socket cavity. A floating member is movable in the socket cavity and an actuator element is operable to provide a force on the floating member such that a corresponding force is distributed to the packaged device when received in the socket cavity such that the plurality of contact pads thereof are in electrical contact with the arranged conductive elements of the conductive element layer.
In various embodiments of the apparatus, the actuator element may be associated with the cover member, the actuator element may be a threaded element movable in a threaded insert of the cover member, and/or the threaded element may include a heat sink head portion with a threaded portion extending therefrom.
In other embodiments, the floating member may be a plate member having a surface configured as a function of a surface of the packaged device with the surface of the plate member positioned in direct contact with the surface of the packaged device when the packaged device is received in the socket cavity, the floating member may include a first surface configured as a function of a surface of the packaged device and a second opposing surface configured as a function of the actuator element with the second surface having an area substantially equal to a contact area of the actuator element, and/or the floating member may be of a pyramid-like configuration.
In yet other embodiments, the cover member includes a hinged member and a closure structure operable to latch the hinged member in a desired position relative to the perimeter wall member, the apparatus may include an alignment structure positioned in the socket cavity to align the contact pads of the packaged device with the plurality of solder spheres of the base member, and/or the conductive element layer may be a conductive elastomer layer.